import { getMenu } from '@/api/user'
import { asyncRoutes, constantRoutes } from '@/router'
import Layout from '@/layout'

/**
 * Use meta.role to determine if the current user has permission
 * @param roles
 * @param route
 */
function hasPermission (roles, route) {
  if (route.meta && route.meta.roles) {
    return roles.some(role => route.meta.roles.includes(role))
  } else {
    return true
  }
}

export function generaMenu (routes, data) {
  const len = data.length
  for (let i = 0; i < len; i++) {
    if (data[i].parentId == 0) {
      const menu = {
        path: data[i].path + '',
        component: Layout,
        alwaysShow: data[i].alwaysShow,
        redirect: data[i].redirect + '',
        name: data[i].name + '',
        meta: { title: data[i].title + '', icon: data[i].icon },
        children: []
      }
      for (let j = 0; j < len; j++) {
        if (data[i].id == data[j].parentId) {
          const viewPath = data[j].component
          const childrenList = {
            path: data[j].path + '',
            component: resolve => require([`@/views/${viewPath}`], resolve),
            name: data[j].name + '',
            meta: { title: data[j].title + '', icon: data[j].icon },
            hidden: data[j].hidden
          }
          menu.children.push(childrenList)
        }
      }
      routes.push(menu)
    }
  }
}

/**
 * Filter asynchronous routing tables by recursion
 * @param routes asyncRoutes
 * @param roles
 */
export function filterAsyncRoutes (routes, roles) {
  const res = []

  routes.forEach(route => {
    const tmp = { ...route }
    if (hasPermission(roles, tmp)) {
      if (tmp.children) {
        tmp.children = filterAsyncRoutes(tmp.children, roles)
      }
      res.push(tmp)
    }
  })

  return res
}

const state = {
  routes: [],
  addRoutes: []
}

const mutations = {
  SET_ROUTES: (state, routes) => {
    state.addRoutes = routes
    state.routes = constantRoutes.concat(routes)
  }
}

const actions = {
  generateRoutes ({ commit }, roles) {
    return new Promise(resolve => {
      getMenu().then(response => {
        const data = response.data
        asyncRoutes.splice(0, asyncRoutes.length)
        generaMenu(asyncRoutes, data)

        let accessedRoutes
        if (roles.includes('admin')) {
          accessedRoutes = asyncRoutes || []
        } else {
          accessedRoutes = filterAsyncRoutes(asyncRoutes, roles)
        }
        commit('SET_ROUTES', accessedRoutes)
        resolve(accessedRoutes)
      })
    })
  }
}

export default {
  namespaced: true,
  state,
  mutations,
  actions
}
